You can expect to earn $2-$5 for most of the surveys in general. For some special surveys you can earn up to $50 per survey but those are rare. Harris Poll also conducts paid focus group studies where you can earn $50-$100 per study. Usually these focus group studies are 1-2 hours long where you interact with other participants under a supervision of a focus group moderator.
Paid survey site companies invest billions of dollars into marketing research online. They always want to find out more intricate details of a consumer's relationship with their product. Whether it's a new television show or just an existing product line, companies like Disney, Samsung, and Sony go to great lengths to find out their ideal audiences.